1. Field of the Invention
The present invention relates to a shake preventing apparatus suitable for use to prevent an image shake due to a camera shake in a camera or the like.
2. Related Background Art
A recent camera has been remarkably electronized and highly automated in respective units beginning from an auto exposure mechanism and an autofocus mechanism. In this type of camera, however, an insufficient part of an attempt of the automation is a measure against an image shake due to an easy-to-occur camera shake when in hand-holding photography.
For this purpose, in this type of camera, a known conventional shake preventing apparatus has the following construction. For preventing a camera shake and especially the image shake caused when the camera is vibrated or tilted, a state of the camera shake is detected by a shake detecting element. A photographing lens system (principal optical system) or an optical system as a part thereof is constructed as a shaking preventive optical system (shaking preventive lens) in accordance with a detected result thereof. This shaking preventive optical system is shifted in a direction orthogonal to the optical axis.
That is, in the camera incorporating such a shaking preventive function, the shaking preventive optical system (hereinafter referred to as a shaking preventive lens) constituting at least a part of the photographing lens system is so supported as to be movable. This shaking preventive lens is shifted in such a direction as to absorb the shake within a plane orthogonal to the optical axis of the principal optical system, thereby correcting a deviation of an image forming position due to the shake and obviating an image shake.
Then, in such a shake preventing apparatus, as a driving mechanism for shifting the shaking preventive lens, there is proposed a mechanism as disclosed in, e.g., Japanese Patent Laid-Open Application No. 3-110530.
The following is a structure in this example of the prior art. A lens frame for the shaking preventive lens is so held as to be movable in the direction orthogonal to the optical axis, and, at the same time, the shaking preventive lens is directly driven and shifted by a driving mechanism (composed of motors, gear trains, a lever or a screw shaft, steel balls and V-grooved portions) while making the lens frame act through a connecting mechanism (composed of a rod member and a driving shaft) for transmitting a driving force from the driving mechanism in the form of a pressing force and a tensile force).
By the way, in the above-described conventional shake preventing apparatus, the apparatus itself is easy to increase in size depending on sizes of the respective units constituting this apparatus and an assembly state. As a result of this, there arises a problem in which the camera increases in size.
An additional problem inherent in the above-mentioned conventional apparatus is that the shake preventing apparatus interferes with lens systems other than the shaking preventive lens system because of each lens system moving largely in the optical-axis direction during photographing in the case of using a zoom lens or the like as a photographing lens optical system. This problem is also inevitable, and it is desired that some measures be taken to obviate those problems.